Is there any advantage in giving improvement exam?

Is there any advantage in giving improvement exam?

i am a student of class +2 giving the cbse board exams. my physics paper prooved to be a nightmare for me and i know i can't get good marks. Now i came to know about the improvement examination and i read its rules in the cbse site. Acc. to them after result we will fill application forms in Aug. and then paper will be held whose result will come in month of May next year. What is the advantage in it ? A student is still wasting 1 year of his life so isn't it better to do +2 again and get better marks in all papers?